Unsupervised lexical substitution for Maltese : steps toward lexical simplification

Abstract

"[Languages] arc a precious component of our cultural heritage and, as such, they deserve future-proofing." This line was taken from the META-NET White Paper Series press release which is a report by META-NET, a European network of research centres working on creating the foundation; for linguistic technology. Unfortunately, another line from the same press release is "Most European languages are unlikely to survive in the digital age" and the Maltese language is not immune to this possibility simply because of the lack of resources dedicated to making Maltese available to the digital world. With new tools come new possibilities and as a language becomes easier to use clue to available tools and resources, it will become more popular. For this reason, it was felt that this project's aim should be to make a contribution to the Maltese language by creating a computational tool for Maltese. This tool should be some form of assistive technology that helps people, such as automatic text simplification, in order to help people who have difficulty understanding complex text. Simplification can be performed on several levels. One such level is syntactic simplification, where it is the sentence structure that is simplified. This level of simplification is currently not within reach for Maltese since it would require complex tools and resources in order to be carried out. So a lower level of simplification was sought. Lexical simplification is simplification at word level with the aim to substitute words that are perceived to be difficult with simpler ones. This level of simplification was more attainable. Lexical simplification requires the existence of a lexical substitution module which substitutes words in a sentence whilst preserving the meaning of the sentence. It also requires the existence of a measure of simplicity which allows the ranking of words according to their perceived difficulty by people. The main aim of this project is to create a lexical substitution system for Maltese, while the secondary aim is to find a useful measure of simplicity for Maltese words. The intention of this system is to be as language independent as possible; therefore, it should be evaluated for both Maltese and English. The fact that standard evaluation tests for English already exist makes English a convenient language to experiment with.